Researcher analyzes factors behind natural menopausal age increase – ScienceDaily
As women age, there are usually two important changes in their bodies that usually occur in adolescence and middle age. The first, known as menarche, is the time of puberty when a girl begins to have monthly menstrual cycles, which often tend to be 8 to 13 years old. She goes into the second change, known as menopause, 12 months after her last menstrual cycle when her ovarian function ceases, usually in her 40s or 50s.
The time after menarche and before menopause is known as a woman’s reproductive lifespan and marks the years when she is most capable of having children. For many women, these events happen naturally. However, women can enter menopause earlier than expected due to other issues. Women who undergo radiation therapy for cancer usually stop their periods, as do women who have menopausal surgeries such as removing their ovaries.
Because each woman experiences these stages of life at different times, one woman’s reproductive lifespan is typically shorter or longer than another, sometimes significantly. Duke Appiah, Ph.D., of the Graduate School of Biomedical Sciences at Texas Tech University Health Sciences Center (TTUHSC), said these differences can affect much more than a woman’s reproductive health.
For example, said Appiah, researchers know there is a link between the length of a woman’s reproductive life and her overall metabolic health, but they don’t know why. Part of that link, he felt, could be caused by a woman naturally exposed to estrogen and various estrogenic compounds. Estrogen can be beneficial because it can help protect or delay the onset of certain health problems. However, they have also been linked to certain diseases, and women who normally have less estrogen and remain so during menopause are more likely to develop heart disease or osteoporosis.
“If the reproductive lifespan is longer, it means that they are still exposed to natural estrogen, which will also help delay certain diseases like cardiovascular disease and osteoporosis, and to some extent even cancer.” , said Appiah.
But why do some women who have a longer reproductive life, and therefore a longer exposure to estrogen, still develop metabolic problems?
That’s a question Appiah and a group of collaborators set out to answer in a research letter to Journal of the American Medical Association (JAMA). The letter, “Trends in age at natural menopause and reproductive lifespan in American women, 1959-2018,” was published in JAMAApril 8 issue. Appiah’s collaborators included Chike C. Nwabuo, MD, MPH, of Johns Hopkins University; Imo A. Ebong, MD, MS, University of California, Davis; Melissa F. Wellons, MD, MHS, of Vanderbilt University Medical Center; and Stephen J. Winters, MD, of the University of Louisville.
Appiah, assistant professor of public health at TTUHSC and director of the university’s master’s program in public health, said women who enter menopause between the ages of 40 and 45 are at higher risk of developing cardiovascular disease, while those who become menopausal after age. in 50 have a higher risk of breast cancer.
“These features have clinical significance, but we wanted to see in the United States over the past 60 years whether there have been changes in age at menopause, reproductive lifespan, and age at menarche. “, explained Appiah. “If that changed, we wanted to know what factors are possibly associated with these changes. Few studies have been done in the United States to look at age trends at menopause. So we can see some of the factors associated with or drive with natural menopause at an early age, maybe we can intervene. “
Appiah said many previous studies were out of date and used data from shorter time periods such as 1910-1950. None of these studies examine the link between age at menopause and the development of metabolic health problems. They also didn’t address the factors that can cause a woman to go through menopause earlier in her life.
To collect data for his study, Appiah used successive surveys covering the National Health Examination Survey I from 1959-1962 (NHES I) through the National Health and Nutrition Examination Survey (NHANES) for 2017-2018. NHANES is a biennial survey conducted by the Centers of Disease Control and Prevention to broadly assess the health of children and adults in the U.S. In addition to providing a much larger sample, NHANES provides a cross-sectional sample of people not institutionalized. American adult population. It includes a detailed demographic and behavioral questionnaire, a physical examination, laboratory tests and a list of all prescription drugs used by the respondent.
From this data, Appiah was able to analyze 7,773 women aged 40 to 74 at the time of the survey who had reached natural menopause. From NHES I 1959-1962 to NHANES 2015-2018, the average age at which women reached natural menopause increased from 48.4 years to 49.9 years and the average age at menarche increased from 13 , 5 years to 12.7 years. This resulted in an increase in the average length of reproductive life from 35.0 years to 37.1 years.
In multivariate fitted models, Appiah found that race and ethnicity (black and Hispanic), poverty, current and former smoking, and use of hormone therapy were associated with early age with natural menopause and a shorter reproductive life. Factors such as more years of schooling and oral contraceptive use were associated with women who reached natural menopause at an older age and had a longer reproductive life.
Appiah said other factors not assessed in their study such as lifestyle and behavior factors, improved access to health care, nutrition, obesity and environmental factors may be related. increasing trends in age at natural menopause and reproductive life.
In previous research, Appiah has shown that menopause is associated with metabolic conditions, which also influence the development of certain diseases. More importantly, he said, his work has shown that researchers tend to be more concerned about the age at which women reach menopause when they actually need to identify the factors that push women forward. to reach menopause at an earlier age, as these factors tend to be more important.
“This study was intended to give empirical evidence to some of my previous studies, but then for future studies I continue to examine how age and menopause are associated with heart structure and function, for example, how the heart beats, how the heart gets bigger with age, “said Appiah.” This article gave some perspective to some of my earlier work, and it also gave some direction to my future work, in which I will examine whether age at natural menopause and length of reproductive life are a marker of overall women’s health. “